Method and device for preventing persons from falling asleep

ABSTRACT

In order to prevent persons driving a vehicle from falling asleep, it is proposed to cool a specific location on the head of the related person. Preferably, the cooling is accomplished by means of a cooled, moving gas or by putting on a plate member ( 10 ) that is in thermal contact with a cooling assembly ( 6 ). Preferably, the cooling assembly ( 6 ) is in the form of a Peltier cell. By locally cooling the head, a sleepy person can be reliably kept awake over an extended period of time.

The present invention refers to a method for preventing persons fromfalling asleep according to the preamble of claim 1 as well as to anapparatus for performing the method according to the preamble of claim 8and claim 14, respectively.

Methods and apparatuses for preventing persons from falling asleep arewell known in the art in various embodiments. By means of apparatuses ofthis kind, it should be ensured, particularly with persons driving a caror guiding a locomotive or an airplane, that a beginning sleepiness canbe postponed for a sufficient time that it can be driven to the nextrest area or the next train stop, respectively, or, in the case ofairplanes, that the pilot can be replaced by another qualified personand that the plane can be safely landed, respectively.

The U.S. Pat. No. 4,203,098 discloses an apparatus of this kind forpreventing a person driving a car from falling asleep that comprises avibrator to be fastened to the seat back of the driver's seat. Thatvibrator is electrically connected to a pulsator to be fastened to thedashboard and which electrically triggers the vibrator. Test conductedwith such an apparatus have shown that the danger exists that the driverbecomes accustomed to the vibrations in the course of time; thus, theapparatus looses its efficiency in the long term.

Thus, it is an object of the invention to propose a method forpreventing persons from falling asleep that operates efficiently andwhich avoids the danger that a person becomes accustomed to it in thelong term.

This object is met by the method described in the characterizing portionof claim 1.

Surprisingly, it has shown that a person tightening with sleepiness canbe reliably kept awake if a specific location on its head, particularlyon its forehead, is cooled, presumed that the sleepiness is causedneither by the influence of alcohol or drugs nor by medication, healthproblems or serious lack of sleep.

Moreover, further tests have shown that persons treated with theproposed method do not shown any sign of getting used to that coolingtreatment, even in the long term.

Preferred embodiments of the method according to the invention aredescribed in the dependent claims 2 to 7.

It is a further object of the invention to provide an apparatus by meansof which the proposed method can be efficiently put into practice.

This object is met by the characteristics defined in the characterizingportion of claim 8 and in the characterizing portion of claim 14,respectively.

Preferred embodiments of the apparatus according to the invention aredescribed in the dependent claims 9 to 19.

In the following, the invention will be further explained, withreference to the accompanying drawings, in which:

FIG. 1 shows a side elevational view of a first embodiment of theapparatus;

FIG. 2 shows a longitudinal sectional view of the apparatus according toFIG. 1;

FIG. 3 shows a side elevational view of a second embodiment of theapparatus;

FIG. 4 shows a longitudinal sectional view of the apparatus according toFIG. 3;

FIG. 5 shows a cross sectional view of the apparatus according to FIG.3;

FIG. 6 shows a longitudinal sectional view of a third embodiment of theapparatus; and

FIG. 7 shows a longitudinal sectional view of a fourth embodiment of theapparatus.

The FIGS. 1 and 2 show a first embodiment of an apparatus that isparticularly suitable for retrofitting a vehicle. The apparatuscomprises a frame 1 having two shackle members 2 that can be put ontothe head similar to goggles, whereby the frame 1 rests not on the nose,but on the forehead. The front face of the frame 1 is provided with arail 3 to which a cooling assembly 4 is connected so as to be slidablealong the rail 3. As the real cooling element, a Peltier cell 6 isprovided. Since the general operation of a cooling device provided witha Peltier cell is known in the art, the following explanations arerestricted to the facts that are essential for the present invention.

The cooling assembly 4 is provided with a housing 5, and in the backside thereof, a fan 8 is received which is directed towards the warmside of the Peltier cell 6. The front side of the cooling assembly 4 isprovided with a circular metallic plate member 10 that is in thermalcontact with the cold side of the Peltier cell 6. Preferably, the warmside of the Peltier cell 6 is provided with a heat sink 11 that iscooled by the fan 8. The supply of electric energy is accomplished bymeans of an electric conductor 13 that is inserted into one of theshackle members 2. The electrical conductor 13 can be provided with anelectric plug by means of which it can be plugged-in directly into thecigarette lighter socket of a vehicle.

The metallic plate member 10 provided at the front side of the housing 5rests on the forehead S of the user of the apparatus once the frame 1has been put onto the head. Thus, a direct contact between metallicplate member 10 and the skin of the user and, thereby, a direct heattransfer is established. Instead of a metallic plate member 10, anotherelement could be used that has good thermal conductive properties. Thedimensions of the metallic plate member 10 preferably amounts to between1 cm² and 3 cm². However, tests have shown that the area of the metallicplate member 10 can amount to between 0.25 cm² and 5 cm² in order toachieve the desired effect of keeping a person awake is ensured, wherebythe minimal area is limited rather by practical than by scientificreasons.

By swiveling the frame 1 and, if appropriate, by displacing the coolingassembly 4 along the rail 3, the cooling assembly 4 can be placedpractically in any arbitrary location of the forehead S. Displacing thecooling assembly 4 is particularly wise when the desired effect beginsto wear off.

Such an apparatus can be stored, for instance, in a mount provided inthe central console of a vehicle. An activation of the cooling assemblycan be accomplished automatically by providing the mount with a contactswitch means that switches the cooling assembly on upon picking-up theapparatus. Another possibility is to provide a manually operated switch.

With the help of FIGS. 3 to 5, a second embodiment of the apparatus willnow be further explained. Thereby, FIG. 3 shows a side elevational viewof the apparatus, while FIG. 4 shows a longitudinal sectional view andFIG. 5 a cross sectional view of the apparatus. In contrast to theembodiment discussed herein before, the cooling is not accomplished bymeans of a metallic plate member to be placed on the forehead, but thecooling is effected by means of a focused jet of air directed to theforehead of the relating person.

The apparatus comprises a housing 20 in which is received a coolingassembly in the form of a Peltier cell 21. Moreover, the apparatuscomprises a fan 23, a nozzle 24, a cooling channel 25 as well as a heatexhaust channel 26 that is connected to a heat exchanger, not visible inthis illustration, be means of a feeder pipe 27 and an outlet pipe 28.In place of a Peltier cell 21, a conventional cooling aggregate, forexample a refrigerator, could be provided as a cooling assembly; in thatcase, the feeder pipe 27 and the outlet pipe 28 would serve fortransporting the corresponding cooling medium. Alternatively, as acooling assembly, a container could be used that is periodically toppedup with a cooled medium, e.g. frozen salt water.

The apparatus is mounted on a flexible tube member 30, the interiorthereof receiving the two pipe 27, 28 connected to the heat exchanger.The electrical conductors 32 required for the operation of the fan 23and the Peltier cell 21 are received in that flexible tube member 30 aswell.

The operation of this embodiment of the apparatus can be explained asfollows:

The fan 23 sucks ambient air that is lead via the cooling channel 25along the cold side of the Peltier cell 21 and thereby cooled down. Thecooled air escapes from the nozzle 24, whereby the latter one isdesigned such that the escaping jet of air is sharply focused and hitsan area on the forehead of the user amounting to between 1 cm² and 5cm².

In order to cool the warm side of the Peltier cell 21, a fluid,preferably water, is provided that circulates through the pipes 27, 28and through the heat exchanger. The heat exchanger can be placed in asuitable location, in a passenger car for example in the room below thedriver seat.

Due to the fact that the apparatus is mounted on a flexible tube member30, the position of the afore mentioned apparatus and, thereby, of thenozzle can be manually adjusted. In this way, both the angle under whichthe jet of cool air hits the forehead of the user as well as theabsolute position in which the jet of air hits the forehead of the usercan be adjusted. It is understood that, alternatively or additionally,the nozzle can be designed adjustable.

Such an apparatus could be directly integrated into the roof structureof a vehicle. Thereby, a swiveling mechanism could be provided by meansof which the apparatus could be swiveled between a rest position and anoperating position. In the rest position, the apparatus could preferablybe received in a recess provided in the roof of the vehicle.

A variant of the embodiment according to FIGS. 3 to 5 could be seen in adesign in which air is used for heat removal instead of a fluid, wherebythe air is lead directly along the Peltier cell, with the result that itwould be not necessary to provide the feeder pipe 27 and the outlet pipe28.

The start-up of the apparatus can either be initiated by the driver orautomatically. For a fully automated start-up, a monitoring means had tobe provided that continuously monitors the driver and starts-up theapparatus as soon a the first signs of sleepiness are observed. Sincesuch monitoring devices are well known in the art, it is not necessaryto further describe them here.

Moreover, it could be considered to provide for an automatic variationof the position of the jet of air and/or of its hitting angle. Further,there could be provided a pulsation of the jet of air, whereby thepulsation frequency should be in the region of some ten seconds up toseveral minutes.

A further mode of realization could be consist in a design in which anozzle is directly or via a flexible tube integrated into the vehicle'sroof structure. The required cooling air could be supplied by the airconditioning system that is probably already present in the vehicle.

Tests have been performed with persons that neither have been under theinfluence of alcohol, drugs or medication nor have health problems or apronounced lack of sleep. Thereby, it has shown that the desired effectof keeping awake takes place even after a short period of operation ofthe apparatus of the invention. However, if the cooling assembly has tobe switched on for a relative long period, e.g. more than five minutes,without the signs of sleepiness having disappeared, it must be assumedthat the relating person already suffers from a heavy overtiredness. Inorder to call the attention of the relating person to this fact, it issuggested to provide a warning device in the apparatus that triggers analarm signal as soon as a predetermined period of operation of thecooling assembly has been exceeded. For this purpose, a shrill alarmtone would be suitable.

FIG. 6 shows a longitudinal sectional view of a third embodiment of theapparatus; it should be noted that this illustration is not drawn toscale. The apparatus comprises a capsule member 32 that is provided witha double-wall housing 33 delimiting a hollow space 34 in its interior.The housing 33 is open at its front side 39. The back side of thehousing 33 is provided with a central opening 35. In the hollow space34, there is received a gas permeable material 36, preferably a spongyand/or porous material, for example in the form of cotton wool orwadding. The material 36 is soaked with a volatile agent that vaporizesor sublimates after having been released, whereby heat is withdrawn fromthe ambient. Finally, the housing 33 is provided with an elastic,circular adhesive tape strip 38 that is located at the front side of thehousing 33. The entire capsule 32 is received in a hermetically sealedpackage for storage, whereby that package is not shown in the drawing infavor of a clearly laid out illustration.

The mode of operation of this capsule 32 can be explained as follows:

After the capsule 32 having been removed from its package, it is pressedonto the forehead of the related person where it remains adhered underthe influence of the adhesive strip 38. Thereby, the absorbent material36 comes into contact with the forehead. Via the opening 35, thevolatile agent can evaporate and sublimate, respectively, whereby heatis withdrawn from the ambient. Since the capsule 32 rests and sticks,respectively, relatively tightly on the forehead of the person, andsince the capsule 32 is provided with a double-wall insulating housing33, heat is withdrawn from the forehead of the related person. Asvolatile agents, for example vaporizing fluids can be taken intoaccount, for example ether, chloroform, esters or lower alcohols, aswell as sublimating solids like naphthalene or camphor. In the case of asolid medium, the use of a spongy and/or porous base material 36 can bedispensed with, if appropriate. The size of the contact area amounts tobetween 0.25 cm² and 5 cm² also in this embodiment.

FIG. 7 shows an alternative embodiment of a capsule member 32. In itshollow space 34, there is received a container 37 that is enclosed bythe spongy and/or porous base material 36. The container 37 serves forstoring the volatile medium and can be broken by an outer mechanicalinfluence. Thus, its content flows into the spongy and/or porous basematerial 36. Preferably, the housing 33 of the capsule member 32 isdesigned to be elastically deformable, such that the capsule member 32can be deformed under the influence of a pressure exerted in thedirection of the arrow P to such an extent that the container breaksopen. Moreover, the inner side of the capsule member 32 can be providedwith break-open elements in the form of spikes 40 whose tips penetratethe container 37 upon exerting a mechanical pressure onto the capsulemember 32, such that the content of the container is, if appropriate, ina dosed manner, released.

For breaking open the container 37, thus, only a certain pressure has tobe exerted onto the housing 33 of the capsule member 32. In this case,it is not mandatory to provide a packaging wrapping the capsule member32, but it may suffice to glue the capsule member 32 onto a carriermember. Certainly, a package could be provided that encloses the capsulemember and that is designed such that the pressure required to releasethe capsule member from the package is sufficient to simultaneouslybreak open the container 37.

It is understood that other designs of such capsule members could bepossible within the scope of the appended claims that differ from theexamples described herein before. For example, the capsule member alsocould be provided, if required, with radial openings through which theheath could be released more efficiently.

A simple realization could be seen in a design in which a plaster isprovided that is filled with a cooling substance. Such a plaster couldbe applied directly to the forehead by the related person, if required.Finally, the method of the invention could be realized also with anaerosol container by means of which a local place on the head could bespecifically cooled.

What is claimed is:
 1. A method for preventing a person from fallingasleep, particularly a person that drives a vehicle or guides alocomotive or an airplane, characterized in that a specific location onthe head of the person is cooled temperature between −10° C. and 10° C.,said specific location on the head of the person having an area between0.25 cm² and 5 cm².
 2. Method according to claim 1, characterized inthat the cooling is accomplished by vaporization or by sublimation of amedium, under withdrawal of the ambient heat.
 3. Method according toclaim 1, characterized in that the cooling is accomplished by means of amoving gas, by gluing on a cooling device (32) or by putting on a platemember (10) that is in thermal contact with a cooling assembly (6). 4.Method according to claim 3, characterized in that the temperature ofthe moving gas or of the plate member (10) amounts to between −10° C.and +10° C.
 5. Method according to claim 1, characterized in that asignal or an alarm is triggered after a cooling period that has exceededa predetermined time interval.
 6. Apparatus for performing the methoddescribed in claim 1, characterized in that a cooling assembly isprovided that comprises a cooling aggregate (6, 21) or a closedcontainer for receiving a cooling agent.
 7. Apparatus according to claim6, characterized in that a cooling aggregate in the form of a Peltiercell (6, 21) is provided.
 8. Apparatus according to claim 6,characterized in that the apparatus comprises a fan (8) that cools thewarm side of the Peltier cell (6) by means of ambient air.
 9. Apparatusaccording to claim 7, characterized in that the apparatus comprises aheat exchanger that is operatively connected to the warm side of thePeltier cell (21) by means of a fluid medium.
 10. Apparatus according toclaim 8, characterized in that a plate member (10) is provided that isin thermal contact with the cold side of the Peltier cell (6), the platemember (10) being provided to be put onto the location of the head ofthe person that is to be cooled.
 11. Apparatus according to claim 6,characterized in that the apparatus comprises an internal fan (23) thatleads ambient air along the cooling assembly (21) and that blows thatair towards the head of the person by means of an adjustable outletnozzle (24).
 12. Apparatus for performing the method according to claim2, characterized in that it comprises a capsule member (32) defining ahollow space (34), a volatile medium being received in that hollow space(34).
 13. Apparatus according to claim 12, characterized in that aporous and/or absorbent material (36) adapted to receive the volatilemedium is located in the hollow space (34) of the capsule member (32).14. Apparatus according to claim 12, characterized in that a container(37) for storing the volatile medium is received in the hollow space ofthe capsule member (32), said container (37) being adapted to be brokenopen by means of external mechanical influences.
 15. Apparatus accordingto claim 12, characterized in that the housing (33) of the capsulemember (32) is elastically deformable.
 16. Apparatus according to claim14, characterized in that the inner side of the capsule member (32) isprovided with elements (40) for breaking open the container (37). 17.Apparatus according to claim 12, characterized in that the housing ofthe capsule member (32) is designed to be thermally insulating andprovided with at least one opening (35) for releasing heat from theinterior (34) of the capsule member (32).
 18. Method according to claim1, characterized in that the cooling is accomplished by means of aPeltier cell or a refrigerator.